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      1 //===- FuzzerIO.cpp - IO utils. -------------------------------------------===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 // IO functions.
     10 //===----------------------------------------------------------------------===//
     11 
     12 #include "FuzzerIO.h"
     13 #include "FuzzerDefs.h"
     14 #include "FuzzerExtFunctions.h"
     15 #include <algorithm>
     16 #include <cstdarg>
     17 #include <fstream>
     18 #include <iterator>
     19 #include <sys/stat.h>
     20 #include <sys/types.h>
     21 
     22 namespace fuzzer {
     23 
     24 static FILE *OutputFile = stderr;
     25 
     26 long GetEpoch(const std::string &Path) {
     27   struct stat St;
     28   if (stat(Path.c_str(), &St))
     29     return 0;  // Can't stat, be conservative.
     30   return St.st_mtime;
     31 }
     32 
     33 Unit FileToVector(const std::string &Path, size_t MaxSize, bool ExitOnError) {
     34   std::ifstream T(Path, std::ios::binary);
     35   if (ExitOnError && !T) {
     36     Printf("No such directory: %s; exiting\n", Path.c_str());
     37     exit(1);
     38   }
     39 
     40   T.seekg(0, T.end);
     41   auto EndPos = T.tellg();
     42   if (EndPos < 0) return {};
     43   size_t FileLen = EndPos;
     44   if (MaxSize)
     45     FileLen = std::min(FileLen, MaxSize);
     46 
     47   T.seekg(0, T.beg);
     48   Unit Res(FileLen);
     49   T.read(reinterpret_cast<char *>(Res.data()), FileLen);
     50   return Res;
     51 }
     52 
     53 std::string FileToString(const std::string &Path) {
     54   std::ifstream T(Path, std::ios::binary);
     55   return std::string((std::istreambuf_iterator<char>(T)),
     56                      std::istreambuf_iterator<char>());
     57 }
     58 
     59 void CopyFileToErr(const std::string &Path) {
     60   Printf("%s", FileToString(Path).c_str());
     61 }
     62 
     63 void WriteToFile(const Unit &U, const std::string &Path) {
     64   // Use raw C interface because this function may be called from a sig handler.
     65   FILE *Out = fopen(Path.c_str(), "w");
     66   if (!Out) return;
     67   fwrite(U.data(), sizeof(U[0]), U.size(), Out);
     68   fclose(Out);
     69 }
     70 
     71 void ReadDirToVectorOfUnits(const char *Path, Vector<Unit> *V,
     72                             long *Epoch, size_t MaxSize, bool ExitOnError) {
     73   long E = Epoch ? *Epoch : 0;
     74   Vector<std::string> Files;
     75   ListFilesInDirRecursive(Path, Epoch, &Files, /*TopDir*/true);
     76   size_t NumLoaded = 0;
     77   for (size_t i = 0; i < Files.size(); i++) {
     78     auto &X = Files[i];
     79     if (Epoch && GetEpoch(X) < E) continue;
     80     NumLoaded++;
     81     if ((NumLoaded & (NumLoaded - 1)) == 0 && NumLoaded >= 1024)
     82       Printf("Loaded %zd/%zd files from %s\n", NumLoaded, Files.size(), Path);
     83     auto S = FileToVector(X, MaxSize, ExitOnError);
     84     if (!S.empty())
     85       V->push_back(S);
     86   }
     87 }
     88 
     89 
     90 void GetSizedFilesFromDir(const std::string &Dir, Vector<SizedFile> *V) {
     91   Vector<std::string> Files;
     92   ListFilesInDirRecursive(Dir, 0, &Files, /*TopDir*/true);
     93   for (auto &File : Files)
     94     if (size_t Size = FileSize(File))
     95       V->push_back({File, Size});
     96 }
     97 
     98 std::string DirPlusFile(const std::string &DirPath,
     99                         const std::string &FileName) {
    100   return DirPath + GetSeparator() + FileName;
    101 }
    102 
    103 void DupAndCloseStderr() {
    104   int OutputFd = DuplicateFile(2);
    105   if (OutputFd > 0) {
    106     FILE *NewOutputFile = OpenFile(OutputFd, "w");
    107     if (NewOutputFile) {
    108       OutputFile = NewOutputFile;
    109       if (EF->__sanitizer_set_report_fd)
    110         EF->__sanitizer_set_report_fd(
    111             reinterpret_cast<void *>(GetHandleFromFd(OutputFd)));
    112       DiscardOutput(2);
    113     }
    114   }
    115 }
    116 
    117 void CloseStdout() {
    118   DiscardOutput(1);
    119 }
    120 
    121 void Printf(const char *Fmt, ...) {
    122   va_list ap;
    123   va_start(ap, Fmt);
    124   vfprintf(OutputFile, Fmt, ap);
    125   va_end(ap);
    126   fflush(OutputFile);
    127 }
    128 
    129 }  // namespace fuzzer
    130